Generally, solenoids comprise a member of magnetically permeable material formed to provide a return path for magnetic flux created by a coil which, when energized, moves an armature which is coaxial with the coil. An example of such a structure is shown in U.S. Pat. No. 4,041,430.
In small solenoids, there is generally provided a bobbin upon which a coil is wound and the bobbin has a central passage or bore in which the armature may move. In many applications, the bobbin is wound with very fine magnet wire which may be 30 gauge or smaller.
Such small magnet wire presents a problem. These small wires have little mechanical strength and therefore, it is necessary to connect them within the container to stronger leads which extend external of the container.
As solenoids are made smaller, a problem is presented in connecting the small magnet wire on the coil to the external leads, and also maintaining a positioning of the magnet wire so there is no shorting of the coil or contact of the magnet wire with the magnetic material of the container or frame.
Accordingly, the present invention provides a new and improved construction for a miniature solenoid which is small enough to fit into a TO-5 transistor can, which is one-quarter inch high and twenty-three sixty-fourths maximum diameter.